Overhead door control device

ABSTRACT

A control device for overhead doors, pivoted about a horizontal axis at or near their upper ends, the control supplementing the closing force to produce an essentially constant closing force, this being accomplished by compound levers backed by a spring, the spring and levers occupying an overcenter position when the door is fully open to yieldably retain the door in its fully open position, and the control also including an extensible and retractable damping means operable, during closing movement, to maintain a relatively slow but constant speed, the damping means releasing its damping resistance, as the door approaches its closing position, to facilitate latching the door.

United States Patent 1 Poe et al.

[451 Nov. 20, 1973 OVERHEAD DOOR CONTROL DEVICE [52] US. Cl. 267/114, 49/205 [51] Int. Cl [58] Field of Search 267/114, 154, 134, 267/141; 244/137; 188/1 C; 49/232, 204,

[56] References Cited UNITED STATES PATENTS 3/1968 Andresen 49/205 1/1958 Neidhart... 267/153 5/1960 Petitpas 49/205 5/1961 Marmont et al. 49/205 9/1956 McAfee et a1 244/137 P Primary Examiner-James B. Marbert Attorney-Charles G. Lyon et al.

[57] ABSTRACT A control device for overhead doors, pivoted about a horizontal axis at or near their upper ends, the control supplementing the closing force to produce an essentially constant closing force, this being accomplished by compound levers backed by a spring, the spring and levers occupying an overcenter position when the door is fully open to yieldably retain the door in its fully open position, and the control also including an extensible and retractable damping means operable, during closing movement, to maintain a relatively slow but constant speed, the damping means releasing its damping resistance, as the door approaches its closing position, to facilitate latching the door.

13 Claims, 9 Drawing Figures BACKGROUND OF THE INVENTION Overhead doors, more particularly doors pivoted about a horizontal axis at or near their upper ends, exert a maximum closing torque or gravity moment when in their full open or essentially horizontal position and essentially zero closing torque, or gravity moment when in their closed position. Automatic closure of an overhead door is desirable; however, the momentum inherent in the free movement of the door is excessive, causing the door to slam shut. If the door is damped sufficiently to prevent excessive initial movement, it cannot be depended upon to close automatically, for the damping force will be too high as the door approaches its closed position. If the door is counterbalanced when fully open, it is excessively counterbalanced at its closed position.

SUMMARY OF THE INVENTION The present invention is directed to an overhead door control device which overcomes the problems previously encountered in such devices and is summarized in the following objects:

First, to provide an overhead door control device incorporating a novelly arranged spring and lever means which exerts a force or moment on the overhead door as it is moved between its closed and open positions, which supplements or opposes the gravitational moment of the door so as to maintain an essentially constant closing force irrespectively of the position of the door.

Second, to provide a control device which is particularly adapted, but not limited to, the control of overhead baggage compartment doors intended for use in passenger aircraft, the control including a novel arrangement of the spring and lever means wherein a reverse or door opening force is exerted as the door approaches its open position so that the door may be yieldably retained in its open position.

Third, to provide a control device, as indicated in the other objects, which incorporates in a novel manner an energy absorbing device such as disclosed in my copending application, Ser. No. 85,001, filed Oct. 29, l970, the energy absorbing device being so arranged as to aid the spring and weight means in maintaining a predetermined closing force, and to release its damping force just prior to closing movement of the door to facilitate latching of the door.

Fourth, to provide an overhead door control device, as indicated in the other objects, which is so arranged that when the door is closed, it is locked against an opening force, until an extraneous means is operated to release the door, thereby preventing, if required, unauthorized opening of the door, or to secure the door against being forced open by excessive shaking of the baggage compartment or its contents.

Fifth, to provide an overhead door control device, as indicated in the other objects, which closes at a preselected rate and resists closing at an appreciably faster rate even though a user should attempt to force rapid closure of the door.

DESCRIPTION OF THE DRA'WINGS FIG. 1 is a fragmentary front view of an aircraft luggage carrier, having a'series of compartments closed by doors, and indicating essentially in outline, the control device.

FIG. 2 is a fragmentary sectional view, taken through 2-2 of FIG. 1.

FIG. 3 is an enlarged view, taken through 3 3 of FIG. 1, showing one of the control' devices in side elevation, indicating a door fragmentarily and. indicating the side frame or panel on which the control device is mounted in broken outline, the control device being shown with its parts in the position assumed when the door is in its closed position.

FIG. 4 is a side'view of the control device, similar to FIG. 3, but showing the parts of the control device in 'the position assumed when the door is in an intermediate position.

FIG. 5 is a similar side view of the control device, with its parts shown in the position assumed when the door is in its fully open position.

FIG. 6- is a fragmentary longitudinal sectional view of a damping unit, showing particularly the damping sleeve.

FIG. 7 is a sectional view, taken through 77 of FIG. 3.

FIG. 8 is a sectional view, taken through 8-8 of FIG. 3, indicating by broken line, a panel on which the control device is mounted.

FIG. 9 is a fragmentary sectional view, taken through 9-9 of FIG. 8, showing particularly the latching mechanism.

For purposes of illustration, the control device is shown as adapted for use in conjunction with overhead aircraft baggage compartments. Each baggage compartment includes a floor or shelf 1, separated from adjacent compartments by partition panels or side frames 2. Extending along the top margins of the compartments is a top trim strip 3. Each compartment is provided with a door 4, intended to pivot about an axis near its upper end and between the panels 2. In the construction illustrated, each door occupies an inclined closed position and is movable through a vertical position to an oppositely directed further inclined open position, as indicated by broken lines in FIG. 2.

Each control device includes a flat housing structure 5, having mounting flanges 6 and 7 which are secured to a side margin of a door 4. For purposes of illustration, each door is shown as provided with two control devices. In practice, however, one control device suffices, the opposite margin of the door being pivoted by a passive pivot or hinge. The housing structure is spaced from the adjacent panel 2 and is provided along selected edges with an edge flange 8, extending into confronting relation with the panel 2. Secured to the panel is a fixed lever or mounting plate 9, having a fulcrum bearing 10 which receives a journal boss 11 extending from the housing structure 5. A bolt or other fastening means 12 extends through the fulcrum bearing 10 into or through the panel 2 and serves to retain the housing structure 5 on the fulcrum bearing. To pre- 'vent rotation of the mounting plate relative to its panel 2, the mounting plate is provided with an arm 13, having a fastening means 14. v

The mounting plate is provided with a secondarm 15, having a mounting boss 16 and pivot pin 17 which journals one end of an arcuate link 18. The arcuate link or lever is joined by a pivotal connection '19 to a second link or lever 20 which, in turn, is joined by a pivotal connection 21 to a mounting boss 22 formed, on the housing structure 5. l i l A thrust unit 23 is interposed between the pivotal connection 19 which joins the levers 18 and 20 and a pivotal connection 24 extending from a mounting boss also formed on the housing structure 5. The thrust unit includes a thrust rod 25, one end of which is joined to The spring, however, is in its extended position and therefore in its weakest position. Thus, the condition is such that the leverage is maximum, but the spring force is minimum. As the door is moved from its closed position towards the intermediate position, shown in FIG. 4, the spring force increases but the leverage produced by 'the links or lvers18 and 20 is reducedfContinuing from the positionf' 'shown in FIGa 4, to the position shownin FIG. 5, namely the full open position; the

the pivotal connection 19, and the other end of which is provided with a socket in which is received a telescoping rod 26. The telescoping rod is joined to the pivot 24. A spring 28, located between end washers 29 and 27, secured respectively to the rods 25 and 26, exerts a force tending to extend the rods 25 and 26.

; An energy absorbing unit 30 is interposed between the mounting plate 9 and the housing structure 5. The energy absorbing unit includes a tubular housing 31, having a mounting foot 32 at one end, joined by a pivot 33 to the housing structure 5. Longitudinally movable in the housing 31 is an energy absorbing sleeve 34, fitied on a mandrel 35, having an attachment tip 36,

' joined by a pivot 37 to the mounting plate 9. Ball detents 38 press into the energy absorbing sleeve 34. The energy absorbing unit is more fully described in my copending application, Ser. No. 85,001, filed Oct. 29, 1970.

As is more fully brought out in the copending application, the degree of energy absorption is dependent upon the depth of penetration of the detent balls 38. In the exercise of the present invention, as will be brought out hereinafter, all or selected portions of the energy absorbing sleeve 34 is provided with a slight taper, as indicated by 39, so that the rate of energy absorption may be programmed to meet load conditions. Also, the extended portion of the sleeve 34 is provided with a clearance channel 40, into which the ball detents enter during the closing movement of the door, to relieve the energy absorbing function as the door closes. Similarly, the portion of the sleeve 34 engaged by the ball detents 38 when the door is in its fully occupied position may be provided with a clearance channel 41.

Secured by one end to the pivotal connection 21 is a latch lever 42, having latch teeth 43, engageable with a keeper bar 44, fastened to the mounting plate 9 and having teeth 45. A spring 46 urges the teeth 43 toward the teeth 45. Pivotally mounted under the mounting foot 32 on the pivot 33 is a pivot plate 47, to which is attached a pull cord 48, one end of which extends to a manually engageable pull member, not shown, which may be carried by the door. The other end of the pull cord terminates in an 'eyelet49 pivotally mounted at the extended end of the latch lever 42.

Operation of the control device is as follows:

In the particular application used to illustrate the invention, the door is in an inclined position when closed; however, if desired, it could be in a vertical position when closed. When the door is in itsclosed position, the axes of the pivots 17, 21 and 24 definea triangle with the pivotal connection 19 between pivots Hand 21, but inwardly with respect to the boundaries of the triangle, so that the thrust unit 23 exerts a maximum force in a direction separating the pins 17 and 21. This force tends to turn the door in a counterclockwise direction, as viewed in FIG. 3; that is, tends to turn the door toward or maintain the door in its closed position.

:springis further compressed, exerting greater force,

and the pivot 24. In doing so, the direction of force is reversed and'the door is yieldably' locked in its open position. I

By proper choice of the spring 28 and links of the le- 7 vers 18 and 20, as well as the physical position of their pivot points for'difi'erent positions of the door, the turn ing force exerted on the door by the spring and the levers may be such as to supplement the effect of gravitational force on the door. That is, in its nearly fully open position where the pivotal connection-19 is not past center, the gravitational force is greatest, whereas, the efiect of the spring force is minimum. As the door moves toward its vertical position, as shown in FIG. 4, the gravitational force is reduced but the effective spring force increases so that the net or total force is the same as when the door was nearly open,

It will be noted that although the door is in a vertical position in FIG. 4, the axis is offset from the door so that a gravitational force still exists, moving the door from the position shown in FIG. 4 toward the position shown in FIG. 3. However, as the door continues to move, the gravitational force reduces and the effective spring force increases so that a constant net force is maintained.

Ideally, the efiective force as applied by the spring to the door would exactly compensate for the change in the effect of gravitational force.

If the door were not restrained, augmenting the force applied to the door so as to drive it toward its closed position, would cause the door to slam closed with greater force than if the door were permitted to swing freely. It is therefore desirable to restrict the rate of movement of the door and this is accomplished by the energy absorbing unit 30. As the detent balls 38 embed in and roll on the absorbing sleeve 34, the sleeve absorbs energy in proportion to the depth of penetration and the rate of movement with respect to the detent balls. If the force to be damped is constant, then the sleeve may be cylindrical and the energy absorption may be constant throughout the range of movement of the door. However, if a constant net closing force on the door cannot be attained, the thickness ofthe sleeve may be programmed so that a constant closing rate may be achieved if a constant rate is desired. If the net closing rate changes uniformly, the sleeve may compensate by being slightly tapered, as suggested diagrammat sition so that the damping efi'ect of the energy absorbing unit ceases and the momentum of the door effects the final latching operation. The actual latching may be accomplished by a conventional latch, not shown, or

the door may be held yieldably in its closed position by the effective force of the spring 28. Still further, a spe cial latching means may be utilized, as represented by the latch lever 42 and keeper bar 44. The teeth 43 and 45 may be arranged for actual engagement when the door is in its closed position, or may be in slight misalignment so that only slight outward movement of the door is required to cause engagement. That is, as shown in FIG. 3, only slight movement of the door will result in interengagement of the teeth. Thus, in order to open the door, the pull cord 48 must first move the latch lever 42 clear of the keeper bar.

In order to limit movement of the latch lever, a stop 50 is provided. A stop 51 engages the pivotal connection 19 when the door is in its closed position to prevent overcenter movement. A stop 52 engages the piv- 'otal connection 19 when the door is in its fully open position to limit the extent of overcenter movement and a stop 53 may engage an end of the keeper bar 44 to limit further movement of the housing structure about the mounting plate, also when the door is in its fully open position.

While the control device is illustrated in conjunction with overhead doors its use is not limited thereto.

While particular embodiments of this invention have been shown and described, it is not intended to limit the same to the details of the construction set forth, but instead, the invention embraces such changes, modifications and equivalents of the various parts and their relationships as come within the purview of the appended claims.

I claim I. A control device for doors disposed between fixed side members and intended to pivot between a first position in which the door exerts a lesser turning force, and a second position in which the door exerts a greater turning force, the control device comprising:

a. a fixed member secured to at least one side member and including a journal defining the intended axis of rotation of the door;

b. a housing structure secured to the door and including a bearing rotatable on the journal to permit movement of the door between its first and second positions;

c. a first lever pivotally connected to the fixed member;

d. a second lever pivotally connected to the housing structure;

e. the levers being pivotally connected to each other;

f. a yieldable thrust unit including a spring pivotally connected to the levers and to the housing structure;

g. the levers and thrust unit being so positioned at each location of the door between its first and second positions to exert, in conjunction with the tuming force, an essentially constant net turning force urging the door toward one of its positions.

2. A control device, as defined in claim 1, wherein:

a. when the door is adjacent its first position, the

thrust unit is in an extended position exerting reduced thrust, while the levers are in their extended relation to apply the reduced thrust with increased leverage;

b. and when the door is adjacent its second position,

the thrust unit is in a retracted position exerting increased thrust while the levers are in a relatively folded relation to apply the increased thrust with reduced leverage.

3. A control device, as defined in claim 2, wherein:

a. upon movement of the door to its second position, the levers are urged past center to cause the thrust unit to exert an opposing force tending to maintain the door in its second position. K

4. A control device, as defined in claim" 1, wherein:

a. an energy absorbing means is interconnected between the housing structure and the fixed member and operable to absorb energy during movement of the door from its second position to its first position.

5. A control device, as defined in claim 1, which further comprises:

a. interengaging latching means carried by the fixed member and the housing structure for locking the door in its first position;

b. and means for releasing the latching means.

6. A control device for an overhead door pivoted near its upper end between frame members for movement between a closed position wherein the door exerts a lesser gravitational turning force and an open position wherein the door exerts a greater gravitational turning force, the control device comprising:

a. spring and lever means interposed between the door and a frame member for applying a varying turning force supplementing the gravitational turning force, to produce in the door a force urging the door toward its closed position;

b. and an energy absorbing means also interposed between the door and a frame member to reduce the rate of movement of the door;

.c. the force exerted on the door by the spring, as

modified by the lever means and damped by the energy absorbing means, producing a constant closing movement of the door.

7. A method of controlling the movement of an overhead door, pivoted near its upper end for movement about a horizontal axis, wherein the door exhibits an increasing gravitational moment as it is moved at least the major portion of its travel toward its fully open position, the method characterized by:

a. applying an augmenting moment to the door which diminishes as the door moves toward its open position and increases toward its closed position, the sum of augmenting moment and gravitational moment being substantially constant throughout the major portion of the door movement 8. A method, as defined in claim 7, which is further characterized by:

a. absorbing energy during closing movement to damp the rate of movement and to maintain an essentially constant closing velocity;

b. and releasing the damping force immediately before the door reaches its fully closed position, to facilitate complete closure.

9. A method, as defined in claim 8, which is further characterized by: g

a. releasably locking the door against subsequent opening movement.

10. A control device for doors disposed between fixed frame members and intended for pivotal movethe first pivot means being positioned in offset relation to the door whereby the door tends to close by gravitational force;

b. second pivot means secured to a frame member in fixed offset relation to a corresponding first pivot means;

c. a first lever arm pivotally connected to the second pivot means;

d. third pivot means secured to the door for movement about the axis of the first pivot means;

e. a second lever arm pivotally connected to the third pivot means;

f. a fourth pivot means interconnecting the first and second lever arms;

g. a yieldable variable force thrust unit pivotally connected to the fourth pivot means and to the door to exert a force opposing the gravitational force and tending to open the door.

11. A door control device as defined in claim 10,

wherein:

a. when the door is in its closed position, the thrust unit exerts a minimum force, while the first and second levers are relatively positioned to apply a compensating maximum force;

b. when the door moves toward its fully open position, the thrust unit exerts increased force while the first and second levers change their relative position to apply decreasing compensating force;

c. and when the door is in its full open position the first and second levers are positioned to augment the force exerted by the thrust unit to hold the door in its open position. I

12. A door control as definedin claim 10, wherein:

a. means are included to vary the position of the second pivot means about the axis of the first pivot means, thereby to change the effective force of the thrust unit and the compensating force of the first and second levers.

13. A door control as defined in claim 10, which further comprises:

a. latching means including interengaging elements carried by the door and a fixed frame member for securing the door in its closed position. 

1. A control device for doors disposed between fixed side members and intended to pivot between a first position in which the door exerts a lesser turning force, and a second position in which the door exerts a greater turning force, the control device comprising: a. a fixed member secured to at least one side member and including a journal defining the intended axis of rotation of the door; b. a housing structure secured to the door and including a bearing rotatable on the journal to permit movement of the door between its first and second positions; c. a first lever pivotally connected to the fixed member; d. a second lever pivotally connected to the housing structure; e. the levers being pivotally connected to each other; f. a yieldable thrust unit including a spring pivotally connected to the levers and to the housing structure; g. the levers and thrust unit being so positioned at each location of the door between its first and second positions to exert, in conjunction with the turning force, an essentially constant net turning force urging the door toward one of its positions.
 2. A control device, as defined in claim 1, wherein: a. when the door is adjacent its first position, the thrust unit is in an extended position exerting reduced thrust, while the levers are in their extended relation to apply the reduced thrust with increased leverage; b. and when the door is adjacent its second position, the thrust unit is in a retracted position exerting increased thrust while the levers are in a relatively folded relation to apply the increased thrust with reduced leverage.
 3. A control device, as defined in claim 2, wherein: a. upon movement of the door to its second position, the levers are urged past center to cause the thrust unit to exert an opposing force tending to maintain the door in its second position.
 4. A control device, as defined in claim 1, wherein: a. an energy absorbing means is interconnected between the housing structure and the fixed member and operable to absorb energy during movement of the door from its second position to its first position.
 5. A control device, as defined in claim 1, which further comprises: a. interengaging latching means carried by the fixed member and the housing structure for locking the door in its first position; b. and means for releasing the latching means.
 6. A control device for an overhead door pivoted near its upper end between frame members for movement between a closed position wherein the door exerts a lesser gravitational turning force and an open position wherein the door exerts a greater gravitational turning force, the control device comprising: a. spring and lever means interposed between the door and a frame member for applying a varying turning force supplementing the gravitational turning force, to produce in the door a force urging the door toward its closed position; b. and an energy absorbing means also interposed between the door and a frame member to reduce the rate of movement of the door; c. the force exerted on the door by the spring, as modified by the lever means and damped by the energy absorbing means, producing a constant closing movement of the door.
 7. A method of controlling the movement of an overhead door, pivoted near its upper end for movement about a horizontal axis, wherein the door exhibits an increasing gravitational moment as it is moved at least the major portion of its travel toward its fully open position, the method characterized by: a. applying an augmenting moment to the door which diminishes as the door moves toward its open position and increases toward its closed position, the sum of augmenting moment and gravitational moment being substantially constant throughout the major portIon of the door movement
 8. A method, as defined in claim 7, which is further characterized by: a. absorbing energy during closing movement to damp the rate of movement and to maintain an essentially constant closing velocity; b. and releasing the damping force immediately before the door reaches its fully closed position, to facilitate complete closure.
 9. A method, as defined in claim 8, which is further characterized by: a. releasably locking the door against subsequent opening movement.
 10. A control device for doors disposed between fixed frame members and intended for pivotal movement about a fixed horizontal axis between a closed position and an open position: a. first pivot means defining the fixed horizontal axis and including fixed elements secured to the door; the first pivot means being positioned in offset relation to the door whereby the door tends to close by gravitational force; b. second pivot means secured to a frame member in fixed offset relation to a corresponding first pivot means; c. a first lever arm pivotally connected to the second pivot means; d. third pivot means secured to the door for movement about the axis of the first pivot means; e. a second lever arm pivotally connected to the third pivot means; f. a fourth pivot means interconnecting the first and second lever arms; g. a yieldable variable force thrust unit pivotally connected to the fourth pivot means and to the door to exert a force opposing the gravitational force and tending to open the door.
 11. A door control device as defined in claim 10, wherein: a. when the door is in its closed position, the thrust unit exerts a minimum force, while the first and second levers are relatively positioned to apply a compensating maximum force; b. when the door moves toward its fully open position, the thrust unit exerts increased force while the first and second levers change their relative position to apply decreasing compensating force; c. and when the door is in its full open position the first and second levers are positioned to augment the force exerted by the thrust unit to hold the door in its open position.
 12. A door control as defined in claim 10, wherein: a. means are included to vary the position of the second pivot means about the axis of the first pivot means, thereby to change the effective force of the thrust unit and the compensating force of the first and second levers.
 13. A door control as defined in claim 10, which further comprises: a. latching means including interengaging elements carried by the door and a fixed frame member for securing the door in its closed position. 